Get the dates of the ‘x’ occurrence of the Weekday within the Month 0

You may want to find for example the date of the 4th Saturday in each month for a given year. This function came out of answering the question here: I’ve created it as a Table Valued Function so you can bind it into any query you wish.   create function dbo.tvfn_dates_of_day_in_month_position ( @year_start date, […]

Using ADO.NET from F# – Examples 0

ADO.NET is dead and replaced many years ago but this week I needed to write a bit of ADO.NET against SQL Server to test out Prepared statements and server side cursors for an application that requires to support it. Here is the fully working example that covers off the bits I needed: You need to […]

The maths most SAN engineers do not understand in context of Database Servers 6

I suppose I write this post to mock some of the things I keep seeing in the industry today. Directly Attached Storage (DAS) has moved on dramatically in the past 5 years, a single SSD has the capability of up to 525MBytes/sec throughput (SATA/SAS 6Gbits/sec), 700MBytes/sec (M.2) and then there is PCIe connected flash operating […]

CISCO VPN Client dropping with “Reason 422: Lost contact with the security gateway” 1

Writing this out of embarrassment but hopefully it will help somebody else if they have the same issue with the CISCO VPN Client or similar. When at my girlfriends I VPN over her WiFi into my client, that’s always worked, but, last Thurs/Friday I started getting issues with the VPN dropping out after just a […]

Entity Attribute Value (EAV) data model meets SQL Server Clustered Columnstore for dramatic performance improvement (Part #1) 2

<sarcasm>Want to have complete flexibility adding/removing attributes without DDL, store all your data in a single database table and still have performance then read on….</> It’s often the complaint of developers they can’t easily adjust the data model and add more attributes to it (columns), rightly or wrongly it happens and it’s a legitimate requirement. Ordinarily data […]

SQL Server Version Upgrade – Don’t follow the myth of migrating to the previous version! 3

I thought I’d put out some thoughts around why I think people who’d rather migrate to or start a project afresh with SQL Server [Previous] are potentially costing themselves a lot of pain, resource and thus cash in the longer term. I’ve been working with SQL Server and Windows since the very early days – […]

How Hekaton (XTP) achieves Durability for “Memory Optimised” Tables 3

“Memory Optimised” tables reside entirely in memory, the operations INSERT, UPDATE and DELETE as well as SELECT are all significantly quicker, but just how is it possible to achieve durability with memory optimised tables while still achieving the significantly higher throughput? Like traditional on-storage tables durability is achieved once the data has been written and hardened off […]

Changing In-Memory Table definition without down time 4

One of the restrictions of a “memory optimised” table is that you cannot modify its definition once created. You may find that once your table has been in use for a period of time it may be apparent you don’t need one of the Hash indexes for example, or perhaps you made a hash (pardon the […]

SQL Server bitmap operators, bitmasks and bit arrays 1

In this post I cover what bitmap and bitmasks are, before I can do that I need to make sure you are up-to speed on binary, base 2 and how the bits are layed out in data. Binary Binary (Base 2) is used throughout computer systems, the Windows platform amongst others relies on it. Base […]

Maximum IOPS for a 10K or 15K SAS Hard Disk Drive is not 170! 5

At times, mmm quite often now actually (perhaps it’s because I’m getting older and more grumpy) the industry I’m part of really makes me embarrassed, all too often folk just quote things they’ve seen on Wikipedia or via word of mouth without even a basic knowledge of the “fact” they are quoting – a “fact” […]

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